Pump control system

ABSTRACT

A fluid supply apparatus and control system, the apparatus including a plurality of independently operated fluid outlets and a plurality of fluid pumps each operative upon demand at the outlets to maintain a supply of liquid at least equal to the demand at the outlets. The control system includes control circuitry, fluid pressure operated switches, and relays for energizing only as many pumps as are required to maintain a given pressure under varying volume delivery requirements.

6 1 1 1 11 :13 ilnite States atent 1 1 1111 3,766 Finger 1 Jan. 22, 1971- 1 PUMP CONTROL SYSTEM 3,229,639 1/1966 Hignutt et al 417 7 x 5] nento John F. Finger, Beresford S. Dak 1,304,529 5/1919 Arnold 137/567 X[73] Assignee: Sioux Steam Cleaner Corporation, P i E i -Willi R CliBeresford, Attorney, Agent, or Firm-Merchant. Gould. Smith 221 Filed;Aug. 28, 1972 [21] Appl. No.: 284,364 [57] ABSTRACT A fluid supplyapparatus and control system, the appai 137/566 5 1 ratus including aplurality of independently operated outlets and a of pumps ch op [58]Field of Search 137/566, 567, 417/5, 6, 7 five upon demand at theoutlets to maintain a Supply of liquid at least equal to the demand atthe outlets. [56] References Cited The control system includes controlcircuitry, fluid UNITED STATES PATENTS pressure operated switches, andrelays for energizing 1,972,812 9/1934 Woolley 417/7 only as many pumpsas are required to maintain a ,8 6 7/1957 Reed 417/7 X given pressureunder varying volume delivery require- 2,sss,s7s 6/1959 BUCk.... 417/7mam 3.135182 6/1964 Gray 137/567 X 2 Claims, 1 Drawing Figure 1 PUMPCONTROL SYSTEM The present invention relates to apparatus for supplyingliquids under pressure to points of delivery such as jet nozzles used inautomobile washing apparatus. In some types of car washinginstallations, the water or liquid is supplied to a plurality of washingmachines or washing booths from a single storage tank or other sourcehaving delivery pressure less than required. In these, a single motordriven pump is usually used, the pump and its motor having a capacitysufficient to supply adequate pressure to all of the booths or machineswhen all of these are operating simultaneously. During off-peak periods,when only one or a small fraction of the total number of booths orwashing machines are in operation, the single pump and its motor operateat a capacity far in excess of what is needed, resulting in a waste ofelectrical power consumed merely in recirculating the washing liquidwithin the system.

SUMMARY OF THE INVENTION An important object of this invention is theprovision of apparatus for supplyingfluid or liquid under pressure to'aplurality of outlets, and of a control system which limits the use ofpower to that which is required to satisfy the demand at said outlets atany given time.

Another object of this invention is the provision of apparatus as setforth in which the power requirement for pumping varies with the demandfor fluid at the outlets.

To these ends, I provide a header having a fluid inlet and a pluralityof outlets for connection to fluid lines having valves controllingdelivery of fluid from the header, a plurality of pumps having inletsoperatively connected to a fluid supply source and outlets operativelyconnected to the header, and drive motors each drivingly connected to adifferent one of the pumps. The pumps are disposed in a parallel fluidcircuit arrangement between the fluid supply source and the header, andthe pumping motors are controlled by electrical control circuitryincluding fluid pressure operated switches in the fluid circuitarrangement. Each of the switches are operatively connected to adifferent one of the pump motors and are each operative responsive topredetermined pressures, different from the operating pressures of theother switches, to control operation of their respective pumps. In thismanner, the number of pumps operating at any given time is dependent onthe fluid pressure in the fluid circuit between the pumps and valveswhen one or more of the valves are open.

DESCRIPTION OF THE DRAWING The single view in the drawing is amechanical and electrical diagram illustrating the invention, some partsbeing broken away.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the diagram, thenumeral 1 indicates a liquid supply source, such as a tank or reservoirfor holding water, preferably for the purpose of washing automotivevehicles. Although not shown, it may be assumed that the reservoir 1 isprovided with an inlet for water from a city main, and with conventionalmeans for heating the water to desired operating temperature. Theapparatus of this invention involves pumping means for delivering waterfrom the reservoir 1 to a plurality of car washing machines atsubstantially higher pressure than is available in most city mains, foreffective cleaning. An elongated header 2 is provided with an inlet 3and a plurality of outlets 4, each of the outlets 4 being connected to adifferent one of a plurality of fluid lines 5 having therein controlvalves 6. It may further be assumed that each of the control valves 6 isdisposed remote from the header 2, each in a different washing booth orassociated with a different car washing apparatus.

In the embodiment illustrated, the apparatus includes conduit meansdisposed to provide a parallel circuit arrangement including conduits orpipes 7 and 8 that are interconnected at spaced intervals by branchconduits 9, 10, 11 and 12, the pipe 7 being connected at one end to thereservoir 1 to provide a discharge therefrom, and at its other end tothe inlet 3 of the header 2. The pipe 8 has an end portion 13 that isconnected to the pipe 7, as indicated at 14. A fluid pump 15 isinterposed in the pipe 7, and is preferably of the centrifugal variety,having a relatively low pressure, high volume delivery capacity. Betweenthe pump 15 and pipe connection 14, the pipe 7 has interposed therein aconventional flow switch 16, and a check valve 17, the check valve 17being disposed between the flow switch 16 and pipe connection 14.

A plurality of relatively low volume, high pressure positivedisplacement pumps 18, 19, 20, and 21, are each interposed in arespective one of the branch pipes 9, 10, 11 and 12, each of the pumps18-21 being operated by a respective one of a plurality of drive motors22, 23, 24 and 25. Between their respective pumps 18-21 and theirrespective connections to the pipe 7, the branch pipes 9-12 are eachprovided with a respective one of a plurality of fluid flow operatedswitches 26, 27, 28, and 29. Also interposed in the branch pipes 9-12,between their respective pumps 18-21 and their respective flow operatedswitches 26-29 are respective check valves 30, 31, 32 and 33. Returnpipes 34, 35, 36 and 37 are each connected at one end to a respectiveone of the branch pipes 9-12, between their respective pumps 18-21 andthe pipe 8, the return pipes 34-37 all being connected to a commonreturn line 38 that extends to the reservoir 1. Each of the return pipes34-37 has interposed therein a different one of a plurality of pressurerelief or unloader valves 39.

The pump 15 is used to maintain a minimum charging pressure within thefluid system, including the header 2, fluid lines 5 to their respectivevalves 6, and pipes or conduits 7-12, including the pipe portion 13.Preferably, the charging pressure provided by the pump 15 is in theneighborhood of ten pounds per square inch. The pump 15 is operated by amotor 40 which, like the motors 22-25, is a three-phase motor controlledby a starting relay 41 including a relay coil 42 and switches 43 thatare closed when the relay coil 42 is energized. The relay 41 furtherincludes a switch 44. The switches 43 are interposed in leads 44a thatare connected to a fused three-wire power line 45. The relay 42 isinterposed in a grounded lead 46, in series with a manually operatedcontrol switch 47, the lead 46 extending from the secondary winding of atransformer 48, the primary winding of which is connected to a pair ofconductors of the power line 45 by means of leads 49 and 50.

Control means for the several pump motors 22-25 includes respective onesof a plurality of motor starting relays 51, 52, 53 and 54, time delayrelays 55, 56, and 57, and a plurality of pressure operated switches 58,59, 60 and 61. The pressure operated switches 58-61 are preferably ofthe type produced by Honeywell Inc. under their trademark PRESSURETROL,and operate to open the control switches thereof responsive to increasein fluid pressure over a predetermined amount within a fluid line. Theswitches 58-61 are operatively coupled to the pipe 8, the switch 58being connected to the pipe 8 between the branch pipes 9 and 10, theswitch 59 being connected to the pipe 8 between the branch pipes and 11,the switch 60 being connected to the pipe 8 between the branch pipes 11and 12, and the switch 61 being connected to the pipe 8 between thebranch pipe 12 and end portion 13 of the pipe 8.

The relay 51 comprises a coil 62, a plurality of motor control switches63, and indicator light switch 64 and a relay control switch 65. Theswitches 63-65 are closed responsive to energization of the relay coil62. The switches 63 are each interposed in one of the leads of atriple-wire conductor 66 connected to the power line 45 and to the motor22. In a similar manner, the relays 52, 53 and 54 include respectiverelay coils 67, 68 and 69, the relay 52 including motor startingswitches 70 interposed in triple line 71 extending from the power leads45 to the motor 23, a light switch 72 and a relay control switch 73, theswitches 70, 72 and 73 being closed responsive to energization of therelay coil 67. The relay 53 includes motor control switches 74, a lightswitch 75, and a relay control switch 76, the switches 74-76 beingclosed responsive to energization of the relay coil 68, the switches 74being interposed in motor leads 77 connected to the power leads 45 andto the motor 24. The relay 54 includes motor control switches 78 and alight switch 78a, these switches being closed responsive to energizationof the relay coil 69, the switches 78 being interposed in motor leads 80connected to the power leads 45 and to the motor 25.

Preferably, and as shown, the control circuitry for the several motors22-25 and 40 is of lower voltage than that of the pump motors 22-25 and40, the lower voltage circuitry including a lead 79 that is connected atone end to the lead 46, and which extends through the light switch 44 ofthe relay 41, and through a lamp 79a to ground. A branch lead 81 extendsfrom the lead 79 through the light switch 64 of the relay 51 and a lamp810 to ground. A second branch lead 82 extends from the lead 79 throughthe light switch 72 of the relay 52, and through a lamp 83 to ground.Another branch lead 84 extends from the lead 79 through the light switch75 of the relay 53, and through a lamp 85 to ground. Likewise, a branchlead 86, connected to the branch lead 84, extends to the light switch78a of the relay 54, and from thence through a lamp 87 to ground.

The coil 62 of relay 51 is interposed in series arrangement with theflow operated switch 26 and pressure operated switch 58 in a lead 88that is connected to the low voltage lead 79. A manually operated switch89 is disposed in the lead 88. The flow operated switch 16 is connectedin parallel circuit arrangement with the flow operated switch 26 by apair of leads 90. The relay 52 is dependent upon operation of the relay51 for energization of its relay coil 67, the coil 67 being interposedin a lead 91 that is grounded at one end, and which is connected at itsopposite end to the lead 79, the switch 65 of the relay 51 beinginterposed in the lead 91. Also interposed in the lead 91 is a manuallyoperated switch 92. As shown, the time delay relay 55 is disposed in thecircuit comprising the lead 91. The pressure operated switch 59 includesa pair of switch sections 92a and 93, the former of which is interposedin the lead 91 in series with the switch 65 of the relay 5] and the flowoperated switch 27. A shunt lead 94, having interposed therein theswitch 93, is connected at one end to the lead 91 between the switch 27and switch section 92, and at its other end to the lead 91 between theswitch 27 and the time delay 55, to shunt out the flow operated switch27. The time delay relay 55 is also connected in a grounded lead 95connected to the lead 91 between the switches 65 and 92.

The relays 53 and 54 are controlled in the same manner as the relay 52,the coil 68 of the relay 53 being interposed in a grounded lead 96 inseries with the time delay relay 56, the flow operated switch 28, theformer of a pair of switch sections 97 and 98 of the pressure operatedswitch 60, the switch 73 of the relay 52, and a manually operated switch99. Like the circuit for the coil 67, the circuit for the coil 68includes a shunt lead 100 in which the switch section 98 is interposed,and which is operative to shunt out the flow operated switch 28. Thetime delay relay 56 is also disposed in a circuit comprising a groundedlead 101 connected at one end to the lead 96 between the switches 73 and99. As shown, the lead 96 is connected to the low voltage control lead79.

The coil 69 of the relay 54 is interposed in a grounded lead 102 inseries with the time delay relay 57, flow operated switch 29, the fomierof a pair of switch sections 103 and 104, the switch 76 and a manuallyoperated switch 105, the lead 102 being connected to the lead 79 bymeans ofa portion of lead 84. A shunt lead 106 connects the switchsection 104 in series with the switch section 103, and is disposed toshunt out the flow operated switch 29. The time delay relay 57 isdisposed in a circuit comprising a grounded lead 107 that is connectedto the lead 102 between the switches 76 and 105.

The flow operated switches 16 and 26-29 are of wellknown conventionaltypes, these switches being open when no liquid flow is present in theirrespective pipes 7 and 9-12. The pressure operated switches 58-61 areset to be closed when pressure in the system downstream from the pumps18-21 reaches predetermined lower limits, and are opened bypredetermined rise of pressure in the system downstream from the pumps18-21. Each of the controls or switches 58-61 are set to open and closeat pressures different from those of the others of the switches 58-61.As an example, the switch 58 may be set to open at a line pressure of700 pounds per square inch, and close when the pressure drops to a pointslightly thereunder. The others of the switches 59, 60 and 61 are set toopen at progressively lower pressures. For example, the switch 59 may beset to open at a line pressure of 650 pounds per square inch, the switch60 to be opened at 600 pounds per square inch, and the switch 61 to openat 550 pounds per square inch. Like the switch 58, the switches 59-61are adapted to close when the line pressure drops to points slightlybelow their respective opening pressures. The arrangement of theswitches 59, 60 and 61 is such that, when pressure is being built up inthe pipe 8, header 2 and fluid lines 5, the switch sections 93, 98 and104 open before their respective cooperating switch sections 92a, 97 and103, as will hereinafter become apparent. It will here be noted that thetime delay relays 55, 56 and 57 are of a type well known to thosefamiliar with electrical controls and, in and of themselves, do notcomprise the instant invention. Hence, further detailed showingand'description of the time delay relays is omitted in the interest ofbrevity.

OPERATION To initiate operation of the supply apparatus, the manuallyoperated switch 47 is closed to energize the coil 42 of the relay 41.Energization of the coil 42 causes closing of the several switches 43and the switch 44 to respectively energize the pump motor 40 and lightthe lamp 79a to indicate that the pump is in operation. The pump 15supplies fluid to the entire system up to the several valves 6. Theseveral manually operated switches 89, 92, 99 and 105 are then closedand the apparatus is ready for use. Opening of any one of the valves 6causes an immediate pressure drop within the header 2 and pipes 7 and 8.Water flowing through the pipes 7 or 8 will cause either switch 16 or 26to close, thus energizing the coil 62 of relay 51, initiating operationof the high pressure pump 18 which not only replenishes the supply ofwater in the pipe 8, header 2 and the opened one of the valves 6, butrapidly builds up pressure within the pipe 8, header 2 and fluid lines5. During operation of the pump 18, the switch 65 is closed to providean energizing circuit for the relay coil 67 through the lead 91 andshunt lead 94. However, the time delay relay 55 is arranged to delayenergization of the coil 67 of relay 52 until such time as pressurebuilds up to a point where switch 59 opens. Thus, the circuit to thecoil 67 is broken before the coil 67 becomes energized. However, shoulda second valve 6 be opened while the first is still open, pressure inthe pipe 8 and header 2 will be reduced to a point where the switch 59is closed. After a predetermined time interval, the circuit will becompleted through the time delay relay 55 to energize the coil 67 ofrelay 52, initiating operation of the motor 23 and pump 19. It will benoted that, once the pump 19 is put into operation, the flow operatedswitch 27 will close so that, after the switch section 93 is open, thecircuit will still be complete through the relay coil 67 until theswitch section 92a is opened by pressure in the pipe 8 rising to the set650 pounds per square inch.

If, during the time that two of the valves 6 are open, a third valve 6is opened, pressure in the pipe 8 and header 2 will drop to a pointwhere the switch sections 97 and 98 of the pressure operated switch 68will close to cause a circuit to be completed through the time delayrelay 56 which, after a predetermined time interval will close thecircuit through the relay coil 68 to energize the motor 24 and initiateoperation of the pump 20 while the pumps 18 and 19 are still operating.While the pumps 18-20 are operating, opening of another valve 6 willcause initiation of operation of the pump 21 in the same manner as abovedescribed with respect to the pumps 19 and 20.

As long as a sufficient number of valves 6 are open to cause a pressuredrop in the pipe 8 and header 2 to a point below 550 pounds per squareinch, or whatever pressure the final pressure operated switch 61 is setat, all of the pumps 18-21 will remain in operation. As soon as any oneor more of the valves 6 are closed, pressure will begin to build up inthe pipe 8 and header 2 until the lowest switch operating pressure, or550 pounds per square inch, is reached. At this time, the switch 61 willopen, thus cutting the circuit to the relay coil 69. Preferably, thetime delay relay 57 will operate to keep the relay coil 69 energized fora predetermined time interval so that the pump 21 will remain inoperation in the event that a closed one of the valves 6 is reopened. Ifthe closed one of the valves remains closed or the number of valves 6 inopen condition is decreased, pressure of liquid in the pipe 8 and header2 will increase to cause deenergization of the motor 24 and its pump 20,motor 23 and its pump 19 in succession, until all of the valves 6 areagain closed, after which the pump 18, alone of the high pressure pumps,will remain in operation until pressure in the pipe 8 and header 2 againreaches the predetermined maximum of 700 pounds, after which the motor22 will be deenergized and the pump 15 will continue to operate tomaintain the minimum charging pressure within the system.

From the above, it will be seen that only a sufficient number of thepumps 18-21 are put into operation to supply the demand ofliquid asdetermined by the number of valves 6 in open condition. When any one ofthe valves 6 are opened, the pump 18 is always the first to be actuated,opening of other valves 6 causing the pumps 19, 20 and 21 to be actuatedin succession. Upon closing of the different valves 6, the high pressurepumps 18-21 are deenergized in the reverse order. Although not shown, itmay be assumed that the relay 51 controlling the motor 22 for the pump18, may be provided with a timing device which will maintain the motor22 in an operating condition for a predetermined time interval after themaximum pressure is reached in the pipe 8 and header 2, so thatreopening of a single valve 6, after the same has been closed for ashort time, will permit the pump 18 to remain in operation, and thusdecrease the number of times of starting and stopping of the motor 22.The pressure relief valves 39 operate to prevent the various pumps 18-21from becoming overloaded during any stage of the water supply operation.

This invention has been thoroughly tested and found to be completelysatisfactory for the accomplishment of the objectives set forth; and,while I have shown and described a commercial embodiment of the fluidsupply apparatus and control therefor, it will be understood that thesame is capable of modification without departure from the spirit andscope of the invention, as defined in the claims.

What is claimed is:

1. In a fluid supply apparatus:

a. a fluid reservoir;

b. a header having fluid inlet means, and outlet means adapted to beconnected to a plurality of fluid lines each have a valve controllingfluid flow from said header;

c. a plurality of fluid pumps each having a fluid inlet and a fluidoutlet;

d. conduit means connecting said pump inlets to said reservoir and saidpump outlets to the fluid inlet means of said header and disposing saidpumps in 7 8 succession in a parallel fluid circuit arrangement 3. eachof said control relays except the last in the between said reservoir andheader; succession thereof including a relay operated e. a plurality ofdrive motors each drivingly conswitch connected in series with thepressure opnected to a different one of said pumps; erated controlswitch and coil of the next sucf. and control means for said drivemotors, comprisceeding relay in said succession, so that operaingcircuitry including: tion of each relay and its respective drivemotor 1. a plurality of control relays arranged in succesfollowing thefirst relay in the succession thereof sion, one for each of said drivemotors, each is dependent upon energization of each precedrelayincluding a relay coil, ing relay in said succession thereof.

2. andaplurality of fluid pressure operated control 0 2. The apparatusdefined in claim 1 in which the switches disposed in said fluid circuitarrangepumps of said plurality thereof are of relatively high ment in asuccession between said pumps and pressure delivery type, and in furthercombination with said header, and each connected in series with alowpressure system-charging pump interposed in said the relay coil of arespective one of said relays, conduit means between said reservoir andsaid plurality the first control switch in the succession thereof ofpumps, and a drive motor for said system-charging being disposed tocontrol the first pump in the pump, said control means including acircuit for said succession of pumps to deliver fluid at apredelast-mentioned driving motor for energizing said motor terminedhigh maximum pressure, the others of independently of the drive motorsfor said relatively said control switches in the succession thereof highpressure pumps, to maintain a given low pressure being disposed tocontrol their respective pumps fluid charge in said conduit meansbetween said reserto deliver fluid at predetermined progressively voirand said high pressure pumps. lower maximum pressures,

1. In a fluid supply apparatus: a. a fluid reservoir; b. a header havingfluid inlet means, and outlet means adapted to be connected to aplurality of fluid lines each have a valve controlling fluid flow fromsaid header; c. a plurality of fluid pumps each having a fluid inlet anda fluid outlet; d. conduit means connecting said pump inlets to saidreservoir and said pump outlets to the fluid inlet means of said headerand disposing said pumps in succession in a parallel fluid circuitarrangement between said reservoir and header; e. a plurality of drivemotors each drivingly connected to a different one of said pumps; f. andcontrol means for said drive motors, comprising circuitry including: 1.a plurality of control relays arranged in succession, one for each ofsaid drive motors, each relay including a relay coil,
 2. and a pluralityof fluid pressure operated control switches disposed in said fluidcircuit arrangement in a succession between said pumps and said header,and each connected in series with the relay coil of a respective one ofsaid relays, the first control switch in the succession thereof beingdisposed to control the first pump in the succession of pumps to deliverfluid at a predetermined high maximum pressure, the others of saidcontrol switches in the succession thereof being disposed to controltheir respective pumps to deliver fluid at predetermined progressivelylower maximum pressures,
 3. each of said control relays except the lastin the succession thereof including a relay operated switch connected inseries with the pressure operated control switch and coil of the nextsucceeding relay in said succession, so that operation of each relay andits respective drive motor following the first relay in the successionthereof is dependent upon energization of each preceding relay in saidsuccession thereof.
 2. and a plurality of fluid pressure operatedcontrol switches disposed in said fluid circuit arrangement in asuccession between said pumps and said header, and each connected inseries with the relay coil of a respective one of said relays, the firstcontrol switch in the succession thereof being disposed to control thefirst pump in the succession of pumps to deliver fluid at apredetermined high maximum pressure, the others of said control switchesin the succession thereof being disposed to control their respectivepumps to deliver fluid at predetermined progressively lower maximumpressures,
 2. The apparatus defined in claim 1 in which the pumps ofsaid plurality thereof are of relatively high pressure delivery type,and in further combination with a low pressure system-charging pumpinterposed in said conduit means between said reservoir and saidplurality of pumps, and a drive motor for said system-charging pump,said control means including a circuit for said last-mentioned drivingmotor for energizing said motor independently of the drive motors forsaid relatively high pressure pumps, to maintain a given low pressurefluid charge in said conduit means between said reservoir and said highpressure pumps.
 3. each of said control relays except the last in thesuccession thereof including a relay operated switch connected in serieswith the pressure operated control switch and coil of the nextsucceeding relay in said succession, so that operation of each relay andits respective drive motor following the first relay in the successionthereof is dependent upon energization of each preceding relay in saidsuccession thereof.